| // Copyright 2017 The Bazel Authors. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package com.google.devtools.build.lib.packages; |
| |
| import com.google.devtools.build.lib.analysis.config.transitions.PatchTransition; |
| |
| /** |
| * Customizable transition which accepts the rule it will be executing on. |
| */ |
| public interface RuleTransitionFactory { |
| /** |
| * Generates a transition to be used when entering the given rule. |
| * |
| * <p>This cannot be a {@link |
| * com.google.devtools.build.lib.analysis.config.transitions.SplitTransition} because splits are |
| * conceptually a property of the <i>parent<i> rule. In other words, it makes sense for a parent |
| * to say "build my deps in configurations A and B". But it doesn't make sense for a dep to say |
| * "build myself in configurations A and B" if its parent doesn't know how to intelligently handle |
| * the results. |
| * |
| * <p>If this class determines that no transition should be performed, it should return {@code |
| * NoTransition.INSTANCE}. |
| */ |
| // TODO(bazel-team): refactor to only take an AttributeMap since that's how it's used anyway. |
| PatchTransition buildTransitionFor(Rule rule); |
| } |